1. Field of the Invention
This invention generally relates to cable mounts. More particularly, it relates to a means and method for mounting transmission lines on antenna towers.
2. Description of the Prior Art
Various mounts, supports, hangers and clamps are employed to secure cables, conductors, and transmission lines to an antenna tower. The mounts are attached at periodic spacings along the legs and structural members of the tower. Since several antennas are often mounted on the tower, dozens of transmission lines may run along the antenna tower. In such instances, multiple cable or cluster mounting systems are used to secure the transmission lines.
The cables are exposed to the elements and are subject to the forces placed upon them by the wind. One cause of cable failure is the breakage of the conductor due to prevailing winds. Even if the cable does not break cleanly, the whipping action caused by the wind may have a cumulative destructive effect on the life of the cable and the tower. Since antenna tower heights can reach a thousand feet, the weight of thousands of feet of cable and numerous mounts must be taken into account when designing an antenna tower structure.
In addition to increasing the weight loading on the antenna towers, multiple-cable mounts may significantly increase the wind load on the tower. Since towers must be designed to withstand these additional loads, the cost associated with designing and erecting a tower is increased.
Another drawback of prior art cable mounts is that they do not allow easy access for the attachment of additional cable hangers. Hangers are often attached to the cross-members of the antenna tower structure, using any available position on the tower. Also, the placement of cable mounts may impede access of maintenance personnel by making it increasingly difficult to climb the tower.
U.S. Pat. No. 4,813,639, issued Mar. 21, 1989 to Midkiff et al., attempts to solve the problem regarding an orderly arrangement of cables. This patent discloses a cluster mounting system for supporting multiple transmission lines along the side of an antenna tower. Midkiff et al. uses a polygon-shaped cable support section which is affixed to a leg of the antenna tower and extends away from the antenna tower support.